An Analysis on Factors Affecting Local Control and Survival in Nasopharyngeal Carcinoma / 대한방사선종양학회지

PURPOSE: This study was performed to find out the prognostic factors affecting local control, survival and disease free survival rate in nasopharyngeal carcinomas treated with chemotherapy and radiation therapy. MATERIALS AND METHODS: We analysed 47 patients of nasopharyngeal carcinomas, histologically confirmed and treated at Chonnam University Hospital between July 1986 and June 1996, retrospectively. Range of patients' age were from 16 to 80 years (median; 52 years). Thirty three (70%) patients was male. Histological types were composed of 3 (6%) keratinizing, 30 (64%) nonkeratinizing squamous cell carcinoma and 13 (28%) undifferentiated carcinoma. Histological type was not known in 1 patient (2%). We restaged according to the staging system of 1997 American Joint Committee on Cancer. Forty seven patients were recorded as follows: T1; 11 (23%), T2a; 6 (13%), T2b; 9 (19%), T3; 7 (15%), T4; 14 (30%), and N0; 7 (15%), N1; 14 (30%), N2; 21 (45%), N3; 5 (10%). Clinical staging was grouped as follows: Stage I; 2 (4%), IIA; 2 (4%), IIB; 10 (21%), III; 14 (30%), IVA; 14 (30%) and IVB; 5 (11%). Radiation therapy was done using 6 MV and 10 MV X- ray of linear accelerator. Electron beam was used for the lymph nodes of posterior neck after 4500 cGy. The range of total radiation dose delivered to the primary tumor was from 6120 to 7920 cGy (median; 7020 cGy). Neoadjuvant chemotherapy was performed with cisplatin+5-fluorouracil (25 patients) or cisplatin+pepleomycin (17 patients) with one to three cycles. Five patients did not received chemotherapy. Local control rate, survival and disease free survival rate were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of survival rates between groups. Multivariate analysis using Cox proportional hazard model was done for finding prognostic factors. RESULTS: Local control rate was 81% in 5 year. Five year survival rate was 60% (median survival; 106 months). We included age, sex, cranial nerve deficit, histologic type, stage group, chemotherapy, elapsed days between chemotherapy and radiotherapy, total radiation dose, period of radiotherapy as potential prognostic factors in multivariate analysis. As a result, cranial nerve deficit (P=0.004) had statistical significance in local control rate. Stage group and total radiation dose were significant prognostic factors in survival (P=0.006, P=0.012), and in disease free survival rates (P=0.003, P=0.008), respectively. Common complications were xerostomia, tooth and ear problems. Hypothyroidism was developed in 2 patients. CONCLUSION: In our study, cranial nerve deficit was a significant prognostic factor in local control rate, and stage group and total radiation dose were significant factors in both survival and disease free survival of nasopharyngeal carcinoma. We have concluded that chemotherapy and radiotherapy used in our patients were effective without any serious complication.

Postirradiation Changes of White Blood Cellsand Lymphocyte Subpopulations in Cancer Patients / 대한치료방사선과학회지

PURPOSE: Radiation-induced alteration in the immune function is well known phenomenon in cancer patients. Our purpose is to evaluate the extent of immune suppression immediately after mediastinal or pelvic irradiation, which include significant volume of active bone marrow in adults. METHODS AND MATERIALS: 48 cancer patients with mediastinal(N=29) and pelvic irradiation(N=19) were the basis of this analysis. Age ranged from 36 to 76 and mean and median value was 57 years, respectively. Sex ratio was 1.3(M:F = 27/21). The immunological parameters were the complete blood cell(CBC) with differenial cell(D/C) count, T cel subset(CD3, CD4, CD8, CD19), NK cell test(CD16,CD56), and serum immunoglobulin (lgG,lgA,lgM) level. RESULTS: The mean value of white blood cell(WBC) was reduced from 7017 to 4470 after irradiation (p=0.0000). In the differential count, the number of lymphocyte, neutrophil, and basophil was markedly reduced with statistical significance(p<0.01) and the number of monocyte was not changed and, on the contrary, that of eosinophil was increased by irradiation.In the lymphocyte subpopulation analysis, the number of all subpopulations, CD3(T cell), CD4(helper T cell), CD8(suppressor T cell), CD16(NK cell), CD19(B cell) was reduced with statistical significance. The mean ratio of CD4 to CD8 in all patients was 1.09 initially and reduced to 0.99 after radiotherapy(p = 0.34), but the proportional percentage of all subpopulations was not changed except CD19(B cell) after irradiation.In the immunoglobulin study, initial values of lg G, lg A, and lg M were relatively above the normal range and the only lg M was statistically significantly reduced after radiotherapy(p=0.02) CONCLUSION: Mediastinal and pelvic irradiation resulted in remarkable suppression of lymphocyte count in contrast to the relatively good preservation of other components of white blood cells. But the further study on the functional changes of lymphocyte after radiotherapy may be necessary to conclude the effects of the radiation on the immunity of the cancer patients.